I would like to add it handles all Official Ubuntu distributions wonderfully Ubuntu Studio is my personal favorite, Xubuntu, Lubuntu Kubuntu, Edubuntu are all supported by System76’s drivers.
I’ve also installed Arch Linux, Fedora 17, PeppermintOS, Fuduntu, Sabayon, Linux Mint and Debian. Each one has their quirks but an experienced Linux user can get the wifi, and Fn keys working without too much effort.
Personally I prefer Ubuntu Studio for it’s XFCE desktop and all it’s Video, Audio, Graphics software out of the box.
If you want to really get customizing you can go with the Ubuntu Minimal install and tweak your system from the ground up and still be able to use Sytem76’s drivers. My only complaint is that their drivers require an official Ubuntu based distribution be running for the drivers to install. So even Mint and other Ubuntu based distros can’t take advantage of the drivers.
Personally I think it’s the best laptop I’ve ever owned. You get a great amount of hardware value for each dollar spent and their computers are built to order. It takes 2-3 weeks but it’s worth it as they offer the latest Intel processors as soon as they become available.